Various types of seat reclining apparatus for vehicle have been proposed so far. For example, a reclining apparatus disclosed in JP61-60753U includes two recliners (angle adjusting mechanisms) each of which having a rotating shaft and used for adjusting an angle of a seat back relative to a seat cushion. One recliner is provided at one side of a vehicle seat in a seat width direction, and the other recliner is provided at the other side of the vehicle seat in the seat width direction, and each rotating shaft of the recliner has an identical rotation axis. The reclining apparatus further includes a connecting shaft positioned between the recliners in order to transmit a drive force from the one recliner to the other recliner. The connecting shaft is positioned in a manner where its rotation axis is eccentric to that of the rotating shafts. The reclining apparatus also includes a gear mechanism provided between each rotating shaft and the connecting shaft in order to transmit the rotation. Because the rotating shaft of each recliner is positioned so as to be eccentric to the connecting shaft, the seat may be relatively easily mounted to the vehicle, and a certain portion of the seat underwhich the rotating shafts and the connecting shaft are provided may not interfere with a passenger's hip, which increases comfortability of the seat.
Another reclining apparatus disclosed in JP63-120944U includes a recliner (angle adjusting mechanism) having a rotating shaft and a motor having a reduction gear and being distanced from the recliner. The rotating shaft of the recliner is eccentric to an output shaft of the motor, and a rotation of the motor is transmitted from the output shaft thereof to the rotating shaft of the recliner by means of a chain. The reclining apparatus also includes a reducing mechanism serving as a stopper to limit an actuation of a seat back so as not to move toward foremost and rearmost positions.
According to the reclining apparatus disclosed in JP61-60753U, during an assembly process, because a plurality of gears comprising the gear mechanism needs to be set in a certain order to a bracket provided at the seat cushion or a bracket provided at the seat back, variations may occur during the assembly process. Such variations may be accumulated; as a result, a level of an assembly precision may be decreased. Furthermore, a level of synchronization between the recliners may be decreased. According to the reclining apparatus disclosed in JP63-120944U, it is not mentioned that a drive force is transmitted between the recliners one of which is provided at one side of the seat and the other is provided at the other side of the seat. Accordingly, the assembly precision and the synchronization may not be of concern.
A need thus exists for a seat reclining apparatus for a vehicle which is not susceptible to the drawback mentioned above.